CVE-2024-43872
📋 TL;DR
A race condition in the Linux kernel's RDMA hns driver can cause CPU cores to remain in interrupt context too long when handling CEQE events under heavy load, leading to system soft lockups. This affects systems using Huawei RDMA hardware with the vulnerable kernel driver. The vulnerability requires local access to trigger.
💻 Affected Systems
- Linux kernel with hns RDMA driver
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Complete system unresponsiveness (soft lockup) requiring hard reboot, causing denial of service for all services on affected system.
Likely Case
Temporary system slowdowns or hangs under specific RDMA workloads, potentially affecting application performance.
If Mitigated
Minor performance impact with proper kernel patches applied.
🎯 Exploit Status
Exploitation requires generating heavy CEQE load through RDMA operations, which typically requires local access and RDMA privileges.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 06580b33c183c9f98e2a2ca96a86137179032c08 and 2fdf34038369c0a27811e7b4680662a14ada1d6b
Vendor Advisory: https://git.kernel.org/stable/c/06580b33c183c9f98e2a2ca96a86137179032c08
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Limit RDMA workload
linuxReduce or limit RDMA operations that generate CEQE events to prevent heavy load conditions.
# Monitor RDMA usage and implement rate limiting if possible
# Consider reducing RDMA-enabled application workloads
Disable RDMA if not needed
linuxDisable RDMA functionality if not required for system operations.
# Check if RDMA is enabled: lsmod | grep rdma
# Unload RDMA modules if possible: sudo modprobe -r rdma_ucm rdma_cm ib_umad ib_uverbs ib_core
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized local users from executing RDMA operations.
- Monitor system for soft lockup events and implement automated alerting for investigation.
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if RDMA hns driver is loaded: lsmod | grep hns && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check dmesg for soft lockup messages after applying patch under RDMA load.📡 Detection & Monitoring
Log Indicators:
- Kernel soft lockup messages in dmesg or /var/log/kern.log
- Watchdog timeout warnings
- System hang reports
Network Indicators:
- Unusual RDMA traffic patterns if monitored
- Sudden drop in RDMA performance metrics
SIEM Query:
source="kernel" AND ("soft lockup" OR "watchdog" OR "BUG: soft lockup")